The NCAA tournament expanded this year. Some questioned the decision, but all the field of 68 has done is give us two more days of drama.

March Madness is arguably the greatest event in sports. Nowhere else can you see athletes pouring their hearts and souls out with so much on the line.

Yet the challenge of creating a bracket that perfectly forecasts the results remains more or less impossible. Picking at random, you have roughly a 1-in-240 billion shot of filling out a perfect bracket. Taking into account that all the games aren't completely random (a No. 1 seed has never lost in the first round), you can improve yours odds to around 1-in-150 million, says the Wall Street Journal.

Not bad, right?

No one has ever produced a perfect bracket — at least not on record. But do know how many times all four No. 1 seeds have reached the Final Four?